Compact label printer

ABSTRACT

A remotely-controlled print module for use in printing labels or the like wherein differential gears are aligned on a common drive shaft and oscillatably driven to a predetermined position controllable by means of a bail shaft extending through gear slots, the gears meshing with type wheels carried on a shaft parallel to the drive shaft. The gears are loaded in one direction by means of cables and springs and, during the remotely-controlled cycle of operation, are stopped at predetermined positions by means of indexing pawls which are selectively energized through electromagnetic solenoids, the stopped position of the type wheels being compatible for striking by print hammers. The differential gears and thus the type wheels are remotely selectively controlled by computer-type commands which allow for versatility of expansion and compactness of packaging of the print module.

United States Patent Bremner et al'.

[ 1 Sept. 12, 1972 COMPACT LABEL PRINTER [73] Assignee: The National Cash Register Company, Dayton, Ohio [22] Filed: July 16, 1970 [21] Appl. No.: 55,361

Primary Examiner-Clyde l. Coughenour Attorney-Louis A. Kline, Wilbert Hawk, Jr. and George J. Muckenthaler [57] ABSTRACT A remotely-controlled print module for use in printing labels or the like wherein differential gears are aligned on a common drive shaft and oscillatably driven to a predetermined position controllable by means of a bail shaft extending through gear slots, the gears meshing with type wheels carried on a shaft parallel to the drive shaft, The gears are loaded in one direction by means of cables and springs and, during the remotelycontrolled cycle of operation, are stopped at predetermined positions by means of indexing pawls which are selectively energized through electromagnetic solenoids, the stopped position of the type wheels being compatible for striking by print hammers. The differential gears and thus the type wheels are remotely selectively controlled by computer-type commands which allow for versatility of expansion and compactness of packaging of the print module.

3 Claims, 9 Drawing PATENTED 3.690.250

sum 2 OF 5 AFIG.3

INVENTORS DAVID F. BREMNER 8 STEPHEN B. SMITH THEIR ATTORNEYS PATENTEDSEP 12 I972 FIG.6

SHEET 3 [IF 5 INVENTORS DAVID F. BRENNER 8 STEPHEN B. SMITH THEIR ATTOR NE Y,

PATENTEDSEP I 2 I972 SHEET 4 [1F 5 INVENTORS DAVID F. BREMNER 8 STEPHEN B. SMITH THEIR ATTORNEYS PATENTED E 12 I9 2 3.690.250

sum 5 or 5 FIG.8

INVENTORS DAVID F. BREMNER a STflEPHEN B. SMITH THEIR ATTORNEYS BACKGROUND OF THE INVENTION by waysand means and in a manner which produce high output from a predetermined input, which is accurate to the nth 'degree, and which'is compact to the extent that such apparatus and equipment, so used, must satisfy the business enterprise where space is limited. Therefore, 'the many business machines and. components therein must be crowded into compact systems to utilize such limited space.

. For a number of years," p'ricelabeling machines have included the customary roll of record material, means driving andguiding-the record material in a path to a printing mechanism, and cuttingmeans positioned to remove the printed record material portion (i. e'.,label) in singular fashion for depositing on the package. The

machines have customarily included a keyboard of well-known type operated by one who must establish or calculate the proper letters or numerals to be printed on the label. They use of such a keyboard is now considered too slow in certain operations and of course is also subject to human error.

While those price labeling machines have been adequate in the majority of business enterprises dealing in packaged goods, the advent of remotely controlled and programmed systems hasled to the necessity for improvements in the labeling and packaging areas. In this connection, the design of many machines applicable to the label-printing field has included the use of type wheels controlled in such 'a manner that selected characters are prepositioned in a cyclic operation for establishing thecorrect attitude and relationship of the parts in accordance with desired input.

The prior art teaches the selective setting and control of various mechanisms for indicating and counting functions wherein the cyclic operation has included the use of control rack and gear members, pawl and ratchet arrangements, and spring-urged actuating means for accomplishing the positioning of the indicating or counting units one such mechanism being shown and described in U.S. Pat No. 2,603,702, issued July 15, 1952, on the application of Jack I. Kern. Another example of the prior art relating to a limiter-type reading, improvements are desired 'in remotely controlled label printers of the type disclosed herein.

SUMMARY OF THE INVENTION The present invention relates to a label printer and, more particularly, to a printer utilizing a compact, remotely-controlled print module wherein the module includes an oscillating differential line meshing with cooperating typewheels, in. turn selectively and in dividually positionable to be struck by appropriate print hammers in accordance with predetermined or programmed logic. The print module includes in the drive line a plurality of differential gears aligned on a shaft and fashioned to be driven in an oscillating manner by means of a double-surface box cam and associated linkage arrangement which is responsive to input signals at predetermined intervals. The differential gears are controlled in speed and direction of rotation by a bail shaft which passes through radial slots in the gears, thebailshaftbeing carried on a line parallel to and spaced from thedrive shaft. The differential gears are positioned in meshing relationship with typewheels having appropriate teeth between surfacemanner to allow close andcompact spacing of them counter with automatic reset using spring-loaded pawls, a predeterrnining wheel, and a counter wheel is disclosed in US. Pat. No. 2,858,985, issued Nov. 4, 1958, on the application of Wilfred A. Blaser, and, ad-

ditionally, US. Pat. No. 3,204,869, issued Sept. 7,

etched characters, the gears being individually loaded in one direction by means of cables and springs so as to be subjected to positive drive conditions.

Located adjacent and in line with the plane of each differential gear is a spring-loaded indexing pawl actuable by an electromagnetic solenoid, which, on signal from the remote control system, if fired to cause the pawl to engage with its associated differential gear and stop such gear at the desired position during its' rotation, so as to present the proper character to the print hammer. The solenoids are mounted in staggered and of the pawls which they actuate during the cyclic operation. A typewheel liner, extending the length of I the typewheels, is carried on arms pinned to the drive shaft, the liner being wedge-shaped to fit the teeth of the typewheels between the characters to insure that all wheels are aligned prior to being struck by the print hammers. An over-ride spring is wound on one of the liner driver support arms to prevent character distortion in the event that a typewheel is not correctly positioned and aligned for being struck by the print hammer.

In accordance with the above discussion, the principal object of the present invention is to provide a label printer having a compact print module.

Another object of the present invention is to provide a print module for a label printer wherein the typewheel position is controlled remotely from the printer.

A further object of the present invention is to provide an oscillatably-operated print module wherein the differential line is loaded in one direction to insure positive drive.

An additional object of the present invention is to provide a compact and efficient print module for printing labels or receipts and including oscillating-line gears and hence oscillating typewheels.

Additional advantages and features of the present invention will become apparent and fully understood from a reading of the following description taken together with the annexed drawings, in which:

FIG. 1 is a front view of a label printer utilizing the print module of the present invention;

FIG. 1A is a view, partially diagrammatic, showing the printer drive line from a prime mover to the print module drive shaft;

FIG. 2 is an enlarged front view of the compact print module of the present invention, with the front plate thereof being omitted for clarity of certain parts;

FIG. 3 is a top view of the print module shown in FIG. 2; 7

FIG. 4 is a bottom view of the module shown in FIG.

FIG. 5 is a right side elevational view of the print module shown in FIG. 2, and additionally including a wiring harness and schematic representation of drive and control units therefor;

FIG. 6 is a left side elevational view of the module shown in FIG. 2;

FIG. 7 is a view taken on the side opposite from that shown in FIG. 2, or a rear view of the print module;-and

FIG. 8 is an enlarged stretched-out view'showing the line-up of the various module shafts as taken'on the line 8-8 of FIG. 2. v

The present disclosure will be principally confined to the print module of the present invention, asgit will be seen that the print module is a complete unit in itself and may thus be applied to any one of a number of business machines where remote control of the type wheels is a desireable feature. The compact print module is particularly applicable in a cash-register-type label printer having other mechanism, as disclosed in U.S. Pat. No. 2,730,038, issued Jan. 10, I956, on the application of Mayo A. Goodbar and Russell G. Pratt; and also isapplicable with feed control mechanism of the type disclosed in U.S. Pat. No. 2,889,769, issued June 9, 1959, on the application of Mayo A. Goodbar, Russell G. Pratt, and Clarence A. Bacher. Although these business machines are provided with keyboards for manual operation, certain of the mechanism is complete in itself and therefore could be used in other designs for automatic operation, such as with the structure of the present invention. Suffice it to say that, in such machines, a supply roll of record material is journaled near the top of the machine, and a strip from the roll is caused to be driven through a chute to a precise position where printing is performed by means of print hammers striking against typewheels bearing characters and where a certain portion of the roll of record material is severed from the strip to be ejected in the form of a printed label. Of course, the severed portion could be in manner and form as a receipt, a ticket, or like record to the transaction. Additionally, the supply roll may have preprinted information thereon, and the function of the label printer is to print further data in certain blank spaces. An example of the latter is the labeling of pre-packaged commodities, where the preprinted data would include the name of the business, the name of the commodity, and the type thereof, while the data to be printed would include the weight, the price per pound, and the total price of the package.

Briefly, the illustrated course of label preparation follows a procedure wherein the label material is fed from a supply roll through a guide chute between a serrated printing cylinder and a rubber tension roller which coacts with the printing cylinder to feed the material past a knife and through a second guide chute connected to the knife, thence into coacting relationship with typewheels and cooperating print hammers, and thereafter to a label-ejecting mechanism comprising two rollers which eject the label from a third chute after it has been severed from the'supply material'by the knife. Specifically, as shown in FIG. 1 of the drawings, there is shown a framework which includes right and left frame members 10 and 12 secured in properly. spaced relationship to each other by a base plate 14 and by various cross frames, rods, and bars, the base plate 14 in turn being secured to a machine sub-base 16. Of course, the framework may be modified from that shown to enclose features and mechanism not considered a part of the present invention. The mechanism for feeding and printing the labels is shown as including a supply roll 17, from which a label strip 18 is fed through an elongated guide chute 19 between a printing cylinder 20 and a rubber tension roller 22, which coacts with the cylinder to feed the strip l8 past a knife 24 and through anintermediate chute 26, connected to the knife, thence into coacting relationship with typewheels 28 and cooperating print hammers 30, and finally to a label-ejecting mechanism comprising rollers 32 and 34, which eject the edge of a label 36 .out of a lower chute 38 after it has been severed from the supply strip 18 by the knife 24.

The printing of selected indicia on the label 36 is accomplished by means of a compact module generally designated as 40 (shown enlarged in FIG. 2) and which includes driven differential mechanism controlled from a computer or like processor through control wiring devices. Referring to FIGS. 1 and 1A, a motor 41 is carried in'the upper left-hand corner of the machine to provide the driving force for the various components therein, the drive line including various transmission gears, clutches, or the like to impart rotary motion to the gears 42 and 43in a vicinity near the print module 40. Although the motor '41 supplies power to other machine components, the drive is herein simply shown diagrammatically from the motor to the gears 42 and 43 (FIG. 1A). The gear 43 meshes with a cam-carrying gear 44, one'portion 45 of the cam being aligned on a pin-type shaft 46. The cam is of a double-surface box type which includes an irregular path to be followed by a stud 47 attachedto a follower bar 48 near one end thereof. The follower bar 48 has an elongated slot 49 for slidingly receiving the shaft 46 therein, there being also a second slot 50 spaced along the bar 48 for receiving a pin 51. With such arrangement, as the gear 44 is rotated by the gear 43, the stud 47 follows the irregular path on the cam and drives the bar 48 in a reciprocating motion through the shaft 46 and the pin 51 riding in the slots 49 and 50. An arm 52, fixed to a further gear 53, has an aperture therein for receipt of a stud 54 secured to the bar 48, the stud forming a pivotal relationship between the arm and the bar. The gear 53 meshes with a small gear secured to a larger gear 55, which, in turn, meshes with a drive gear 56 for driving in oscillating fashion the differentials of the print module 40. As understood from FIGS. 1 and 1A, all of this drive train is supported from the framework, which, in turn, supports a front plate 57, to which the print module 40 is attached. Although other ways and means could be devised and provided for driving the differential gears of the print module, the disclosed elements are very effective to convert a rotary motion at the gear .43 to a desired clockwise and then counterclockwise oscillating motion at the differential drive gear 56 (FIGS. 1 and 1A). l

The print module 40 itself includes a mounting plate 58 to which are attached solenoids 59 (FIGS. 2, 3, 5, and 7), each of which is energized or activated through electrical leads 60 and 61 (FIG. 5). Since there are a plurality of such solenoids, differential gears, indexing pawls, and typewheels making up the print module, it is apparent that a detailed description of a single line-up of these parts is sufficient to teach the embodiment of the invention. Exceptfor the different locations of the solenoids 59 in a staggered manner (see FIG. 5) for actuating the closely-spaced indexing pawls and differential gears, the structure is very similar for each of As understood from FIG. 2, two types of solenoids 59 are provided the pull type and the push type. The op three and the bottom three of such solenoids (FIG. 5) are of the pull typeand include plungers pivotally connected to the associated pawls at points removed from the pawl portions 96, thereby extending the springs 95 when swinging the tips into engagement with teeth of the gears 66.

The six remaining solenoids positioned in the central portion of the print module (FIG. 5, dotted-line showing) are of the push type, wherein the plunger of each is pivotally connected to the pawl adjacent the tip portion 96, so as to extend the spring 95 when pushing the pawl tip into contact with a selected tooth of the associated differential gear 66 to interrupt rotation of the gear as the proper character on the connected type wheel is the twelve columns of controlled typewheel printing provided, as shown in FIGS. 4, 6, and 8.

a a The typewheel-setting mechanism of the module 4 comprises a shaft 62 driven in oscillating fashion through the drive gear 56, the gear beingkeyed to the shaft, whichextends through and is joumaled in a front plate63 and a rear plate 64, and which plates are secured to the solenoid mounting plate 58 by suitable screws 65. The shaft 62 carries a plurality of differential gears 66 spaced thereon (FIGS. 3, 4, and 6), the gears having teeth 68 (see also FIGS. 2 and 7) for engaging with companion gear slots 70 of the typewheels 28 journaled on a shaft 73 parallel to the shaft 62 and carried by the plates 63 and'64. Each of the'differential gears 66 has a radially-spaced slot 74, through which a bail 76 extends for urging the gears 66 in one direction and for allowing the gears to rotate independently of the urging thereof, the bail being held parallel to the shaft 62 by means of front and rear arms 78 and 80 (FIG. 6) pinned to the shaft 62 so as to move therewith. As seen in FIG. 2,'each of the differential gears 66' has a second radially-spaced sl0t82, opposite the slot 74, for receiving a stop shaft 84 (seealso FIG. 7) secured to the plates 63 and 64 positioned parallel to the main shaft 62 and to the bail 76. The shaft 84 acts as a stop element against the urging of springs loading the gears 66 in one direction and also as a stop element to limit the amount of travel of the gears in the other direction. As in the case of the bail 76 and the slots 74, the slots 82 permit the gears 66 to rotate independently of the stop shaft 84 during the oscillating motion.

Referring to FIGS. 2, 3, and 7, a plurality of upper and lower indexing pawls 90a and 9011 are oriented and pivotally supported in a manner compatible and aligned with the solenoids 59 and with the differential gears 66, each of the upper pawls 90a having a body portion pivoted on a pin 94 and loaded in a counterclockwise direction (FIG. 2) by a spring 95 secured to a crossshaft 95a. Likewise, each of the lower pawls 90b is pivoted at the pin 93 and loaded in a clockwise direction (FIG. 2) bya spring 95 secured to a cross shaft 95b. Each of the pawls 90a and 90b is so positioned for actuation by its associated solenoids 59 that a tip portion 96 thereof is moved to engage the teeth of the associated differential gear 66 and to stop said gear in such a position as to cause a predetermined character on the typewheel 28 controlled by the associated gear to be presented to the print hammer 30.

moved into print-hammer-aligned position. The springs 95, being so extended in each instance, are-seen to be effective for restoring the interconnected'pawl to. its normal, differential-gear-non-engaging, position (as i1- lustrated in FIGS. 2 and 7) immediately upon deenergization of the respective push or pull solenoid 59. A solenoid plunger restrictor 106 (FIGS. 2 and 7). is spaced from the solenoid support plate 58 and secured thereto by means of a long stud 107. Upper and lower pawl stops 108 and 109, extending substantially between the plates 63 and 64, are also secured to the support plate 58 to limit the movement of the pawls a and 90b against the action of the springs when engaging with teeth of the differential gears 66.

A typewheel liner 110 (FIGS. 6 and 8), of wedgeshaped configuration, so as to fit between'the character teeth of the typewheels 28 (FIGS. 2 and 7), extends the width of the typewheels and is pivotally supported by arms 111 and 112 from the side plates 63 and 64. Upon being driven during machine operation by an arm 113 secured to the differential shaft 62, the liner 110 engages ,the typewheels and aligns them in correct position for being struck by the print hammers 30. The arm 113 extends radially from the shaft 62 (FIGS. 2, 4, and 8) and has a stud 114 at its end for engaging with a lower end cam portion 115 (FIG. 2) of a liner-actuating arm 116, which is pivoted on the same studas is the support arm 111 of the liner 110. The actuating arm 116 carries an upper stud 117 (FIGS. 2 and 3), to which is attached one end of a tension spring 118, the other end of the spring being connected to a stud 1 19 in the plate 63. The spring 118 exerts a force on the actuating arm 116 to maintain the liner 110 in a counterclockwise direction (FIG. 2) and out of the path of the typewheel teeth until the typewheels are all positioned and ready for impact by the associated print hammer 30. The arm 116 has an additional stud 120 engageable by a cam portion of the support arm 111, and, additionally, the side plate 63 carries a stud 121 to limit movement of the arm 116 in a counter-clockwise direction. A small torsion spring 112 (FIG. 2) is provided around the liner pivot hub, with one end thereof connected to the stud 120 and the other end connected to a stud on the side of the support arm 11], the spring thus acting to exert a small force on the liner 110 but in opposition to the tension of the spring 118 to prevent character distortion in the event that one typewheel is not correctly positioned in the line-up ready for printmg.

J As further seen in FIG. 2, each of the differential gears 66 is spring-loaded in a clockwise direction'by means of a cable 130 secured to a gear stud 131 (see also FIG. 8) and trained around a cable-bearing shaft or roller 132 and connected to one end 133 of a spring 134, the other end 135 of said spring being secured to either of two shafts 136, 137 fixed between the side plates 63 and 64, these shafts being spaced to allow for freedom of movement of the springs 134 in a compact assembly.

Referring now to FIG. 5, the print module solenoids 59 of the present invention are connected by the leads 60 and 61 through a terminal block 140 and by a multiconductor cable 141 to a computer device 142, such device being in the nature of a scale or the like for automatically weighing and pricing each package presented thereto. Connected to the device 142 by means of a cable 143 is.a commutator 144, in turn connected to the motor 41 by a cable 145. So that signals can be transmitted'from the computer device'to the-motor, a further cable 146 connects 'these components to complete the. loop of transmitting and receiving signals for operation of the system.

In the operation 'ofthe compact label printer, the unit is turned on, with the motor 41 providing motive power for allcomponents of the machine-The supply strip 18 is fed downwardly through the guide chutes 19 and 26, and, when the label is in position for printing, the computer or like remote control device gives the signal to the print module 40 to print a particular line of type thereon. When the system is energized and running, the commutator 144-monitors the positions of each typewheel 28 in the print module 40 and transmits this information to the computer device 142. At the command from the computer device to start a cycle that is, when the data such as weight and total price is determined for a particular package, the proper line of print is selected through the print module by the computer.

The module main shaft 62. begins its oscillating motion and rotates first clockwise from the position shown in FIG. 2 at a precise speed controlled by the doublesurface box cam drive 45, each of the differential gears 66 being then spring-loaded in the clockwise direction by means of its cable 130 and spring 134, so that the gear follows the bail shaft 76 in the shafts control of direction and speed of such gears.

During suchclockwise rotation of the shaft 62, the bail 76 is seated at one end of the differential gear slot 74 and thus maintains 'all the differential gears 66 at the same attitude until one of the solenoids 59 is energized for actuating its associated pawl 90a or 90b to interrupt the clockwise rotation of the selected gear. The fixed shaft 84 rides in the gear slots 82 and acts as a stop element for those gears not interrupted during the clockwise portion of gear movement. Since each of the differential gears 66 is meshed with an associated typewheel 28, the wheel is driven by such gear but in the opposite, or counter-clockwise, direction, as viewed in FIG. 2. As mentioned above, the position of each typewheel is constantly and continuously communicated to the remote control device 142 by the commutator 144, which interfaces the attitude of each wheel to the computer. As a result of the computers knowledge of the exact position of each typewheel,

when any one typewheel is approaching with a character which is to be printed, the solenoid 59 corresponding to that differential gear 66 is energized by means of capacitor discharge, and the solenoid is held in the energized position by the lower level current.

The firing of the solenoid causes the end tip portion 96 of its associated'pawl a or 90b to enter between the teeth of the differential gear to a controlled depth limited in a swingable path by the stop element 108 or 109, which causes the gear '66 and its corresponding typewheel 28 to stop with the proper character presented to the type hammer 30. The firing of one or more of the solenoids 59, as dictated by the desired line of print on the label, thus interrupts the rotation of the selected differential gear 66 and its typewheel 28 at a precise position for printing. Due to the length of the slot 74 in each differential gear 66, the bail 76 is allowed to continue in its clockwise movement and thus leave that particular differential 'gear inits stopped position. Whichever of the gears 66 are not then stopped or interrupted in their rotation will continue to rotate undisturbed until they are stopped by computer signals in like manner. Of course, those gears which are not called upon to position a typewheel for printing will continue to rotate until the end of the clockwise cycle, where they are positively stopped at a typewheel-nonpositioning or blank character position.

The second slot 82 in the differential gears 66, in conjunction with the fixed shaft 84 running therethrough, limits the travel of each gear to the blank character position of the wheel, the shaft becoming seated against the end of the slot.

After all gears 66 have been stopped, with the associated typewheels thus positioned in the above manner, the main shaft 62 continues its clockwise rotation another slight amount and, by reason of the stud 114 contacting the cam portion 115 of the arm'116, causes the typewheel liner to engage the groove between the character teeth in each typewheel to align all the wheels 28 just prior to the printing operation. After the liner has engaged the groove to precisely hold all the type wheels, the main shaft 62 pauses to so maintain all said wheels in their correct printing positions. During the above-described typewheel-setting cycle (clockwise oscillation of the shaft 62), the appropriate mechanism has fed the strip 18 of label material downwardly a predetermined distance, severed a label 36 from the strip, and positioned the label in its correct printing attitude. At this point in time, the print hammer 30, being spring loaded and cocked, is

released, and the printing on the label 36 is accomplished.

Simultaneously with the release of the print hammer 30, the commutator 144 allows power to be removed form the solenoids 59; however, the typewheels 28 are held in position because the liner 40 remains in mesh with the wheels. Of course, with power removed form the solenoids, the spring-loaded pawls 90a and 90b will automatically move out of contact with the teeth of the differential gears 66.

After the print hammer 30 has contacted the typewheels 28 and the printing on the label has been accomplished, the main shaft 62, being controlled by the double-surface box cam 45 and the slotted follower bar 48, starts return rotation counter-clockwise, as

' character seen in FIG. 2. This motion releases the liner 110 from engagement with the typewheels 28, and the liner immediately moves back to its rest position under urgence of the spring 1 18. The main shaft 62 continues to rotate counter-clockwise, causing the bail 76 to again contact the ends of the slots 74 in the differential gears 66, which, in turn, main shaft 62 and the bail 76 continue to move back to their starting positions against the action of the springs 134, thus causing all gears 66 and wheels 28 to be reset to their original positions and ready for the next cyclic operation.

rotates them counter-clockwise. The

During the above reset portion of the cycle of the main shaft 62, the printed label 36 is fed through the guide chute 38 and ejected from the machine through the rollers 32 and .34. With such ejection and reset completed simultaneously, the machine is now ready to accept the next command from the remote control computer 142.

It is thus seen that herein shown and described is a compact label printer of the module type for printing in response to commands from a remote'control device for setting the typewheels in correct positions. The print module includes a positive differential drive line addedbythe spring loading of the differential gears to position the type wheels for accurate printing on the labels. While only one embodiment has been disclosed for the construction and operation of the print module, certain variations on the/above may occur to those skilled in the art, so it is contemplated that all such variations having these features are within the scope of the invention.

What is claimed is:

lJA compact print mechanism comprising a plurality of differential gears commonly aligned on a driven shaft,

means for driving the shaft in oscillating manner, a

plurality of type wheels cooperating with and driven by the differential gears, the type wheels having teeth thereon with grooves therebetween engaging with the gear teeth,

spring means connected to the differential gears for driving the gears in one direction of travel, each of the gears having a radially-spaced slot therein, a

bail shaft positioned along the gears and carried within the slots and secured to and spaced from the driven shaft for controlling direction and movement of the gears, said spring means exerting continuous biasing on said gears and permitting the bail shaft to be driven independently of the gears during the oscillating movement,

pawl means pivotally supported in relation to the differential gears for engagement with selected gears, and a plurality of remotely-energized solenoids for actuating the pawl means to engage with the selected gears at predetermined positions during one portion of their driving cycle to stop the selected gears for presentation of characters on the type wheels in position for printing.

2. A compact print module comprising a first plate and a second plate space therefrom, a

differential shaft journaled from and extending between the plates, the shaft carrying a plurality of 10 slotted individually-journaled differential gears in aligned fashion,

me s for oscillatabl drivin the aft, spri ri g means conne ted to 51c differential gears for driving the gears in one direction of travel, a plurality of type wheels journally supported from the plates and engaged by the differential gears to be rotated thereby, a bail shaft spaced from the differential shaft and movable therewith along a path in the gear slots for controlling direction and movement of the gears by permitting selected gears to cease movement and allowing other gears to be driven therebeyond in one direction, and for drivingly returning all the gears in the other direction, a plurality of pawls pivotally supported from the plates and adapted to. engage with selected gears at predetermined intervals in said one direction, and solenoid-means for actuating the pawls to engage with the selectedv gears at predetermined positions during one portion of their oscillatingmovement in said one direction, thereby stopping the-engaged gears for presenting type wheel characters for printing thereof. i I o 3. In a label printer having remotely controlled type wheels, the combination of a supply of record material,

means for feeding the record material in a path past the type wheels,-a

driven shaft, a v

plurality of difi'erential gears journaled on the shaft and rotatable independently of each other, each of the gears having a first and a second slot radially spaced therein, a

bail shaft connected to the driven shaft and operable within the first slots-for controlling direction and movement of the gears,

means for driving the differential gears in oscillating manner about the shaft, the gears being engaged with the type wheels to position the wheels for printing during one portion of oscillation, said means for driving including a plurality of springs connected to the printer and to the gears for driving said gears in the type wheels setting direction of travel and a pair of arms secured to the driven shaft for moving the bail shaft in a path of controlled movement cooperable with the spring driving of the gears during said one portion of oscillanon,

stop means adjacent the driven shaft and operable within the second slots for limiting movement of the gears at the end of said one portion, said bail shaft moving with the driven shaft to collectively 

1. A compact print mechanism comprising a plurality of differential gears commonly aligned on a driven shaft, means for driving the shaft in oscillating manner, a plurality of type wheels cooperating with and driven by the differential gears, the type wheels having character teeth thereon with grooves therebetween engaging with the gear teeth, spring means connected to the differential gears for driving the gears in one direction of travel, each of the gears having a radially-spaced slot therein, a bail shaft positioned along the gears and carried within the slots and secured to and spaced from the driven shaft for controlling direction and movement of the gears, said spring means exerting continuous biasing on said gears and permitting the bail shaft to be driven independently of the gears during the oscillating movement, pawl means pivotally supported in relation to the differential gears for engagement with selected gears, and a plurality of remotely-energized solenoids for actuating the pawl means to engage with the selected gears at predetermined positions during one portion of their driving cycle to stop the selected gears for presentation of characters on the type wheels in position for printing.
 2. A compact print module comprising a first plate and a second plate space therefrom, a differential shaft journaled from and extending between the plates, the shaft carrying a plurality of slotted individually-journaled differential gears in aligned fashion, means for oscillatably driving the shaft, spring means connected to the diffErential gears for driving the gears in one direction of travel, a plurality of type wheels journally supported from the plates and engaged by the differential gears to be rotated thereby, a bail shaft spaced from the differential shaft and movable therewith along a path in the gear slots for controlling direction and movement of the gears by permitting selected gears to cease movement and allowing other gears to be driven therebeyond in one direction, and for drivingly returning all the gears in the other direction, a plurality of pawls pivotally supported from the plates and adapted to engage with selected gears at predetermined intervals in said one direction, and solenoid means for actuating the pawls to engage with the selected gears at predetermined positions during one portion of their oscillating movement in said one direction, thereby stopping the engaged gears for presenting type wheel characters for printing thereof.
 3. In a label printer having remotely controlled type wheels, the combination of a supply of record material, means for feeding the record material in a path past the type wheels, a driven shaft, a plurality of differential gears journaled on the shaft and rotatable independently of each other, each of the gears having a first and a second slot radially spaced therein, a bail shaft connected to the driven shaft and operable within the first slots for controlling direction and movement of the gears, means for driving the differential gears in oscillating manner about the shaft, the gears being engaged with the type wheels to position the wheels for printing during one portion of oscillation, said means for driving including a plurality of springs connected to the printer and to the gears for driving said gears in the type wheels setting direction of travel and a pair of arms secured to the driven shaft for moving the bail shaft in a path of controlled movement cooperable with the spring driving of the gears during said one portion of oscillation, stop means adjacent the driven shaft and operable within the second slots for limiting movement of the gears at the end of said one portion, said bail shaft moving with the driven shaft to collectively return the gears against the urging of the springs during the other portion of oscillation, pawl means positioned in relation to the differential gears to engage therewith for stopping rotation of the gears at predetermined positions during said one portion of oscillation, and electromagnetic means for actuating the pawl means to interrupt selected differential gears in response to the remote control. 